1. Field of the Invention
The present invention relates to an image reading and recording apparatus such as a facsimile machine that includes recording means of performing recording on a sheet as a recording medium and means of reading an image from a sheet.
2. Related background Art
As an image reading and recording apparatus such as a facsimile machine, there has been a structure in which a conveyance path for conveying recording sheets and a conveyance path for conveying documents are partially integrated for the purpose of size and cost reductions. FIG. 6 is a schematic vertical cross-sectional view of a conventional image reading and recording apparatus in which a conveyance path for conveying recording sheets and a conveyance path for conveying documents are partially integrated. In FIG. 6, the image reading and recording apparatus includes an ASF unit (auto sheet feeder) 101, an ADF unit (auto draft feeder) 102, an auxiliary conveying roller (auxiliary conveying means) 103, a main conveying roller (main conveying means) 104, a discharge roller (discharging means) 105, a reading unit (a scanner unit) 106, and a recording unit 107.
The ASF unit 101 is an automatic feeder that supplies recording sheets stacked on a stacking table to the apparatus main body separately from one another. The ADF unit 102 is an automatic feeder that supplies stacked documents to the apparatus main body separately from one another. The auxiliary conveying roller 103 is a roller for conveying the recording sheets or the documents supplied from the ASF unit 101 or the ADF unit 102, and constitutes the auxiliary conveying means with a pinch roller that is in contact with the auxiliary conveying roller 103. The main conveying roller 104 is a roller for conveying each recording sheet or each document at a predetermined speed, and constitutes the main conveying means with a pinch roller that is in contact with the main conveying roller 104. The discharge roller 105 is a roller that discharges the recording sheets or the documents to the outside of the apparatus main body, and constitutes the discharging means with a spur. The reading unit 106 constitutes means of reading image data from documents. The recording means 107 records an image on each recording sheet, based on the image data.
In the above-described structure, the auxiliary conveying roller 103, the main conveying roller 104, and the discharge roller 105 are used for both recording sheets and documents. Also, the guide member that forms a conveyance path is shared, so as to reduce the size and costs of the image reading and recording apparatus. A facsimile machine with such a structure is disclosed in U.S. Pat. No. 5,727,890.
Since the above-described conventional structure has the reading unit 106 on the upstream side of the main conveying roller 104 (on the upstream side in the conveying direction), the auxiliary conveying roller 103 is provided for the purpose of stabilizing the unstable conveying speed (the feeding speed) of the ADF unit 102 and conveying each recording sheet to the main conveying roller 104. In practical use, however, this conventional structure differs from a structure having conveying means and conveyance paths provided respectively for recording sheets and documents, only in that the discharge roller is used for both recording sheets and documents. Therefore, the size and cost reductions of the apparatus main body are not sufficient.